As monsoon weather takes a break in the Valley, the heat works overtime. Into the Labor Day weekend there will be triple-digit temperatures, hitting 110 degrees by Sunday. 

Mark O’Malley, with the National Weather Service in Phoenix, says excessive-heat warnings have been issued for Sunday and Monday.

“It will take until next weekend, well after Labor Day, for the pattern to change and become more favorable, possibly get some more consolidated thunderstorms down into the Phoenix Metro,” O'Malley said. 

Emergency heat relief stations will be open at several Salvation Army locations when an excessive-heat warning is in effect. But that excludes federal holidays, like Labor Day this Monday. 

In northern Arizona, the Grand Canyon is also warning hikers about the heat.

In July, the Grand Canyon recorded 543,000 visitors — the highest monthly total for 2022 — and large crowds are expected this weekend.

Spokesperson Joelle Baird is warning hikers to be careful.

“If people are intending to go on a day hike in the inner canyon, especially coupled with the inner heat warning that we are seeing over the next few days, we really want to make sure people are prepared with food and water with them at all times and that they know their abilities," Baird said.

Baird urges visitors to avoid hiking between 10 a.m. and 4 p.m. She also warns hikers to hydrate and be mindful that certain trails do not have water available on-site.